(Neither)
I have seen many different definitions of rocket stoves, but the features that all have had in common are:
1. Dedicated intake
2. Dedicated exhaust
3. Insulation
You feed sticks into the top half of the hole you see. Air comes through there and through the bottom half. There is an equally-sized vertical tube. The sticks burn in the elbow and the heat and smoke go up. This has more airflow than normal fires and between that and the insulation, it is supposed to burn more efficiently.
Except this does not have insulation.
I cleaned out a cupboard and found buggy oatmeal. Mom does not want insects in her compost pile, so I wondered what kind of charcoal it would make. The King of Random made charcoal by putting sticks, paint sticks, and a few different wood-like objects in a paint can with small holes in the lid and setting that on a campfire until the smoke pleased him.
He used three quart paint cans. Those are $3 at Home Depot. I bought one one-gallon can for $5 and built a fire in this garbage can before I cut the hole. It created a huge amount of smoke and when I was bored of tending the fire only the top layer of the buggy oats were black.
I fanned the flames with a pizza box just to keep the smoke away from me, but it definitely made the fire bigger. Smaller cans would have had a larger surface area, so you could argue that is more efficient, but I like one gallon for $5 instead of four quarts for $12.
Does it take at least 140% more time and fuel to do it my way?
First I drilled holes through adjacent corners on the large brick on top of the pile of bricks, but every time I tried to start a fire inside, the match went out.
Then I tried normal bricks, but that did not work without mortar. There is a 1/16th" gap in between the bricks, and they are not insulated, either.
The King of Random claimed he bought ten fire bricks for $33. Not fake fire bricks that Home Depot, Lowe's, and Amazon sell six for $33, but real ones. I cannot find those in the White Mountains or even the Phoenix area. The cheapest ones I found were ten dollars each.
Shipping bricks is cost-prohibitive.
So, I decided to follow TKoR's backyard foundry design to make a rocket stove. You can make one for under $20 if you only count the sand and plaster of Paris.
Not the metal bucket, two plastic buckets, hole saw, or the other materials that add up to $135 if you use his Amazon links.
He also did not include the U-bolts he uses for handles on the donut lid or the arbor or mandrel for the hole saw.
Instead of forming it around a plastic bucket I used an small empty oatmeal tub. Instead of drilling out the side I used another empty oatmeal tub. I printed off sine wave patterns, cut the ends to fit, and taped them together. That was too short, do I did it again with leftover poster board and taped that around the tubs.
I felt concerned the mix would crush the cardboard, so I filled it with a can of Great Stuff that looked at me wrong.
I removed the dried foam with a crowbar and the stove worked well enough, but thus far a rather uninspiring thing. If it were not so heavy I would throw it in the garbage and move on with my life.